JP2667791B2 - Simultaneous production method of purple sweet potato pigment and food material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a stable purple sweet potato pigment excellent in heat resistance, light resistance, etc., and a purple sweet potato which uses the cake after extracting the pigment as a useful food material and eliminates industrial waste. The present invention relates to a method for simultaneously producing a pigment and a food material.

[0002]

2. Description of the Related Art Red-based natural pigments such as red cabbage, grape, and purple corn belong to anthocyanin-based pigments. Purple sweet potato is also a pigment raw material containing a similar anthocyanin pigment. Recently, this dye is excellent in heat resistance and light resistance as compared with other anthocyanin-based dyes, so that it is expected to be used for foods, and various studies have been made on its production method. For example, a method for producing a purple sweet potato pigment by extracting raw or steamed purple sweet potato with water or hydroalcohol under acidic conditions and adsorbing and concentrating the extract (JP-A-62-
297363, Japanese Patent Laid-Open No. 62-297364), the raw material is treated at 10 ° C. or lower, or a frozen and pulverized raw material is used to extract the enzyme activity suppressed with water or hydrous alcohol, A method of producing a purple sweet potato dye by subjecting the extract to treatment such as adsorption and concentration (Japanese Patent Application Laid-Open No. 4-103669) has been proposed.

[0003] However, the technology studied so far is that purple sweet potato as a raw material is limited to Yamakawa purple, Tanegashima native, Ei purple, Chiran purple, Kiire purple, Nakamurasaki, etc., and these contain anthocyanin pigment content. However, the dye was difficult to extract, and there was a limit to industrial use in terms of extraction efficiency and quality of the extracted dye. In addition, it is well known to those skilled in the art that the anthocyanin dye is faded by oxidase contained in the raw material, but it is easy to extract the dye from the crushed material while cooling the raw material to avoid this. It has been considered and implemented by each company for some time. However, this method complicates the manufacturing process and causes local heat generation during pulverization. Therefore, the raw material is, for example, -10 ° C. or −3 ° C. using liquid nitrogen or a freezer.
It is necessary to cool to 0 ° C. and finely pulverize, which limits the industrial use.

In addition, an anthocyanin dye is used under acidic conditions.
Moreover, the extraction method under strong acidic conditions of pH 4 or less has been conventionally considered to be preferable, but when the residue after the extraction of the pigment is used as a food material, the taste of the acid and the modification by the acid affect the taste and texture. It had a significant effect, which was one of the obstacles that prevented the use of lees as a food ingredient. In addition, in the past, after extraction of the pigment, the pigment was difficult to be extracted, so purple streaks with a faint color were seen and it was not suitable as a food material in appearance, and even if the fiber was strong and steamed, it was a normal commercial product It did not become a high-starch food material like sweet potato and was disposed of as industrial waste without any other use.

[0005]

DISCLOSURE OF THE INVENTION The present invention is directed to improving the purple sweet potato itself, which is a raw material, and to provide a production method capable of efficiently producing a pigment and, at the same time, using the extracted cake as a useful food raw material. With the goal.

[0006]

Means for Solving the Problems The present inventors can efficiently obtain a large amount of high-quality pigment from purple sweet potato and use the extracted residue as a useful food material without turning it into industrial waste. After intensive studies, the present invention has been achieved. That is, the present inventors have developed for the first time an improved variety "Kyushu 113" in which the improved variety "Kyushu 109" with Chiran purple as a mother and Yamakawa purple as a father and a mother mated with Satsuma Hikari as a mother, After examining the method of extracting the pigment suitable for the variety, the purple sweet potato cut into chips or the like as necessary was immersed in neutral to acidic hydrous alcohol, or with or without cutting the raw material. It was found that the raw material may be crushed or stirred with a mixer or the like in the presence of an acidic to acidic hydrous alcohol. It was found that the raw material may be with or without the skin on it, and that the raw material need not be cooled and may be treated at room temperature. Of course, the raw material may be processed by cooling and freezing, or may be processed in an environment in which the raw material is replaced with an inert gas such as nitrogen gas. Sufficient quality by simply immersing the cut into a neutral to acidic hydrous alcohol at room temperature and / or crushing or stirring the raw material in the presence of a neutral to acidic hydrous alcohol at room temperature. It was found that a high content of dye solution was obtained.

[0007] By this method, almost all of the dye in the raw material can be extracted. When a liquid and a solid are separated by a conventional method such as filtration or centrifugation, the dye liquid of purple sweet potato is separated.
It is also possible to obtain a white extract cake with almost no pigment. If the extraction conditions are adjusted, the color of the extracted cake can be freely prepared as white to dark purple, that is, white, light red, red, bright red, dark red, light purple, purple, bright purple, dark purple, etc., purple paste It is possible to make yam bean jam or imitation of red bean bean jam, but this is a purple paste that looks like a paste obtained from conventional purple sweet potato as raw material. There is a great difference visually and in texture from the texture that has been given, and the result shows that "Kyushu 113" is superior as a food material. However, in terms of taste, “Kyushu No. 113” had bitterness, which was a major problem. However, those processed by the production method according to the present invention completely eliminate the bitterness, so that they can be used as food materials for the first time. Became.

[0008] The extracted cake from which the pigment has been sufficiently extracted has almost no change as compared with ordinary sweet potatoes, and its tissue is not strong in fiber but rich in starch, and has not only the appearance but also the texture as compared with ordinary commercial sweet potato. There was no change. However, when water containing no alcohol or water-containing alcohol having an alcohol concentration of less than 20% is used for the extraction of the pigment, the extraction rate of the pigment is low, the stability of the extracted pigment is low, and the extracted cake is textured. It becomes dull and unfavorable, and in terms of taste, the bitterness remains unfavorably like the raw material in which no pigment is extracted at all. The hydrous alcohol used both for extracting the pigment and for using the extracted meal as a food material is preferably an alcohol having 3 or less carbon atoms, that is, methanol, ethanol or propanol,
The alcohol concentration was preferably from 20 to 95%, and more preferably from 30 to 80%. The liquidity may be neutral to acidic, but for the use of the extracted meal as a food material, it is strongly acidic, that is, under the conditions of pH 4 or less, the taste of the acid and the modification by the acid greatly affect the taste and texture. Not preferred.

The obtained dye solution may be used as it is or may be purified by a column or the like. In addition, the pigment may be concentrated as it is or purified to obtain a concentrated pigment, or may be powdered by a spray drying method or the like. Heat treatment such as batch sterilization or plate sterilization may be performed in order to prevent discoloration of the dye solution and growth of bacteria. The condition in this case is 80 for batch sterilization.
30 to 60 minutes at １００100 ° C. was sufficient, and 20 to 30 minutes at 100 to 120 ° C. was sufficient in plate sterilization.

The obtained extracted cake can be used as it is, can be cooked and pasted by a conventional method, or can be used as a useful food material as a dried product or a powdered product using a drum dryer or the like. It is also useful as feed. If necessary, sugars, seasonings, etc. may be added to the extracted cake, and the dried product or powdered product may or may not undergo the steaming step.

[0011]

The present invention will be described in more detail with reference to the following examples. Example 1 1 kg of an improved purple sweet potato variety "Kyushu 113" was cut into a 1-5 mm dice with a cutting machine, and immediately 3 L of 80 kg was cut.
% Ethanol solution, stirred at room temperature for 3 hours, and filtered to obtain a purple sweet potato extract pigment solution. This solution was used as Diaion HP-21 (adsorption resin manufactured by Mitsubishi Kasei Industries) 100
After adsorbing the dye, the dye was eluted with 150 ml of 58% ethanol after washing with water. The obtained dye solution was concentrated to 50 g with a vacuum concentrator,
15 g of 5% by volume ethanol, 1 g of citric acid and 34 g of water were added to obtain 100 g of purple sweet potato dye solution. In addition, the extracted lees were steamed in a steamer, added with 150 g of granulated sugar and 3 g of salt, kneaded, and further lined to paste 1.1.
kg. Experimental Example 1 The dye solution obtained in Example 1 exhibited a vivid red-purple color when added to a carbonated beverage, and did not show any color change or insoluble matter even after being kept at room temperature for one month. Moreover, when the paste obtained in Example 1 was wrapped in rice cake and tasted, it was a delicious potato paste Daifuku rice cake. Example 2 5 kg of purple sweet potato improved variety "Kyushu 113"
It was cut into a stick having a length of 15 cm or less at a corner, put in a basket of wire mesh, covered, and immediately poured into 3 L of a 30% methanol solution, and the basket was shaken at room temperature for 5 hours to obtain a purple sweet potato extract pigment solution. . This solution was adsorbed on 100 ml of Diaion HP-21 (adsorption resin manufactured by Mitsubishi Kasei Kogyo Co., Ltd.), washed with water, and the adsorbed dye was eluted with 150 ml of 58% ethanol. The obtained dye solution is applied to a membrane having a molecular weight cut off of 100,000 (Nitto Electric Industries, Ltd.)
The solution was passed through an ultrafiltration membrane NTU-35100) and then concentrated to give 9
15 g of 5% ethanol, 1 g of citric acid, and 34 g of water were added to obtain 100 g of purple sweet potato dye solution. In addition, the extracted cake remaining in the basket is fried together with the basket with oil at 100 to 150 ° C., kneaded with 20 g of starch syrup, 50 g of granulated sugar and 10 g of water, entrapped with syrup that has become candy-like, and dried.
Obtained 00g of potato kempi. Experimental Example 2 The dye solution obtained in Example 2 was added to a vitamin C beverage having the formulation shown in Table 1, and stored in a 50 ° C constant temperature bath for 10 days. As a result, it was found that this dye exhibited extremely good stability. The state of the change over time at this time is shown in Table 2 as the residual rate when the absorbance at the maximum absorption wavelength at the start is 100%.
Shown in Further, when the sweet potato kempi obtained in Example 2 was tasted, it did not change in terms of texture or taste at all from a commercially available one.

[0012]

[Table 1]

[0013]

[Table 2]

Experimental Example 3 In the same manner as in Example 1, instead of "Kyushu No. 113", a dye solution was prepared by using the purple sweet potato conventional varieties Yamakawa purple, Tanegashima native, Chiran purple and Nakamurasaki as raw materials. The extracted cake was made into a paste and compared with the paste obtained in Example 1. As a result, the absorbance value (hereinafter referred to as color value) at the maximum absorption wavelength of the 10% concentration of the dye solution is as shown in Table 3, and "Kyushu 113" has 4 to 5 times higher dye yield than the conventional varieties. , And the pigment was easily extracted. As shown in Table 4, the paste was unpreferable because it had a poor texture and a faint purple appearance.

In the same manner as in Example 1, instead of stirring in an 80% ethanol solution for 3 hours, the mixture was stirred for 25 minutes to obtain a paste from the extracted cake (hereinafter referred to as the paste of Experimental Example 3). As compared with the paste, the appearance was much deeper and more vivid, although the appearance was the same as that of the conventional purple sweet potato paste, and the texture was the same as that of a conventional commercial sweet potato. In terms of taste, neither the paste of Example 1 nor the paste of Experimental Example 3 felt any bitterness, which was favorable as a food. Furthermore, 1 kg of "Kyushu 113" was steamed in a steamer in the same manner as in Example 1 without any extraction treatment of the pigment, and granulated sugar 150 was added.
g and 3 g of sodium chloride were added and kneaded, and the mixture was further strained to prepare a paste (hereinafter referred to as untreated paste), and the taste was compared with that of other pastes. The untreated paste has a strong bitterness, cannot be used as a food material, and has a color that is not vivid and turbid, and is clearly inferior to the pastes of Example 1 and Experimental Example 3. Was. Table 4 shows the results.

[0016]

[Table 3]

[0017]

[Table 4]

[0018]

According to the present invention, a high pigment yield of 4 to 5 times or more can be obtained in a simple process as compared with the case of using conventional purple sweet potatoes, and the extracted residue is not used as industrial waste. It can be used as a useful food ingredient. Moreover, the color of the food material thus obtained can be freely adjusted from white to dark purple, and it can be applied to various uses.

Claims (3)

(57) [Claims] An improved variety of purple sweet potato "Kyushu 113"
Of a purple sweet potato dye, which is treated with a hydrous alcohol under neutral to acidic conditions. 2. An improved variety of purple sweet potato "Kyushu 113"
Treated with hydroalcoholic under neutral to acidic conditions,
A method for simultaneously producing a purple sweet potato pigment and a food material, wherein the cake after pigment extraction is converted into a paste and / or a powder. 3. An alcohol concentration of the hydrous alcohol is 20 to
3. The production method according to claim 1, wherein the content is 95%.